Johnson & Starley have some superb replacement forced air units
with advantages:
- Electrostatic air filters -recommended for asthmatics.
- Modulating burners
- Modulating fans
- Very quiet.
- They also cool by moving air in summer.
- No rads.
- Even temperature around rooms
- Rapid room temperature heat up
- Room Temperatures can be set to a few degrees lower
- No water leaks
- No sludging up of radiators and boilers
- Outside air ventilation can be added
- Heat recovery from extracted air can be added.
- Heat recovery from air extractors can be incorporated.
- Humidification can be added without much hassle.
Try all that with rads.
The modern forced air units by J&S are a world away from the older units
too. They will transform a system. The reason forced air is not installed is more due to ignorance and lack of skills.
Some forced air units have wet copper coil heater batteries heated by a boiler. Many use high flow combis, so DHW is taken care of. That means the boiler heats via air ducts rather than radiators. The system can be slit, forced air and rads.